The principal investigator (PI) is a clinically experienced internist in epidemiology and a National Institute of Health Research Training Fellow with research preparation earned through a MPH. The PI recently investigated gender differences in the extent of coronary artery disease (CAD) among subjects who underwent coronary angiography. Although women had a greater number of coronary risk factors, they were found to have less disease on angiogram compared to men. Women were also less likely to undergo non-invasive diagnostic tests prior to coronary angiogram. The specific aim of the study is to evaluate gender differences in the utilization of coronary angiography in patients with acute myocardial infarction (MI). A historical prospective design will be used to study a cohort of Kaiser Permanente patients with acute MI, hospitalized for a first MI from 1989 to 1991. Stratified random sampling will be used to abstract medical records of 500 males and 500 females from four Kaiser Facilities (two with high procedures rates, two with low). This study improves on previous studies in that only patients with acute MI will be selected, to ensure equalization of disease prevalence and severity between gender. By selecting patients who were members of Kaiser Health Plan, the important confounder variable, insurance status, will be controlled. In order to permit control of other potential confounding variables such as age, race, comorbidities, demographic factors, extent and severity of disease and complication from acute MI, medical records will be extensively reviewed. Charlson Comorbidities Index will estimate each patient's comorbid conditions; Gustafson and Dubois Severity Indices will estimate disease severity. Logistic regression analysis will be used to control for the effects of potentially confounding variables to determine if gender is related to the use of coronary angiography. Kaiser Division of Research will collaborate and donate computer time, work space and onsite expert consultations of senior researchers. The research development will be sponsored by Professor Erika Froelicher, who has performed investigations in the area of gender and CAD. Support and guidance will be ensured by an advisory committee consisting of faculty and researchers from the University of California, San Francisco and the Stanford University, expert in the field of research design, CAD epidemiology, health care utilization and policy studies. The PI intends build on previous research and to explore an important research question that has significant health policy implications; specifically, in terms of overuse and underuse of diagnostic procedures and subsequent management of patients with CAD.